The present invention concerns a safety system for operating at least one electrically actuated locking apparatus of a door of a motor vehicle including a crash sensor, adapted to sense an accident event, and a pre-crash sensor, adapted to recognize a possible imminent accident event. According to the invention, when the crash sensor senses an accident event within a first specified interval of time, the locking apparatus remains bolted for a second specified interval of time, which is sufficiently long to include an entire temporal sequence of the accident event. The apparatus is subsequently unbolted.
A device for protecting occupants of a motor vehicle in the event of a rear-end collision with a measuring device is known from German document DE 35 07 381 A1. This known device measures the distance to an object penetrating into the range lying before the motor vehicle. An evaluation switch activates a protective apparatus in the event of an undershot of a specified distance, so that protective action is completely deployed at the time of a subsequent crash. Such protective action can, for example, consist of securing the motor vehicle doors against flying open.
An automatic safety system for motor vehicles that is controlled by a driver-side reflex is described in German document DE 27 51 821 A1. At a certain degree of actuation of the brake, the doors are automatically bolted, among other things, so that, in the event of a crash (collision), the occupants are not thrown out of the motor vehicle.
Moreover, a method for steering a reversible occupant protection apparatus in a motor vehicle, with a sensor unit recording driving state data, is known from German document DE 101 21 386 C1. Emergency braking, oversteering, or understeering are monitored as driving state data. The occupant protection device is triggered as a function of such data.
A retention belt system for a seat in a motor vehicle with a seat belt and a belt tightener to secure a passenger on the seat is furthermore described in German document DE 44 11 184 C2. The distance to an object and the corresponding relative speed is ascertained, and the expected time until a possible collision between the motor vehicle and the object can be determined on the basis of these parameters. A control unit generates a control signal which increases the power of the belt tightener in time before the possible collision. If a collision can be avoided, the force of the belt tightener is lowered again.
One object of this invention is to provide a safety system for operating at least one electrically actuated door locking apparatus of a motor vehicle with a crash sensor for sensing an accident event, which makes optimized protection in relation to safety systems known from the state of the art available to occupants during a critical driving operation before an unwanted opening actuation.
This object is accomplished by way of a safety system as mentioned above in which the pre-crash sensor, upon recognition of a possible imminent accident event, actuates a central locking unit in such a way that the locking apparatus of the door is bolted for the first specified interval of time, and in which the first specified interval of time has a length such that the possible accident event, if it occurs, falls in the first specified interval of time.
A pre-crash sensor, provided in accordance with the invention, actuates the central bolting unit upon recognition of a possible imminent accident event in such a way that the locking apparatus of the door is bolted for the first specified interval of time. Again, this first specified interval of time has such a length that the occurrence of the possible accident occurrence falls in the first specified time interval. The safety system for operating the electrically actuated locking apparatus of the door of the motor vehicle has a crash sensor for sensing an accident event. When the crash sensor senses the accident event within the first specified time interval, the locking apparatus remains bolted for a second specified interval of time, which has such a length that it includes the entire temporal sequence of the accident event, and is subsequently unbolted. With the safety system of the invention, optimal protection against unintended opening during a critical driving operation is furnished, owing to which occupant safety is improved. The locking apparatus of the door is already barred by the central bolting against an unintended opening of the door when a possibly imminent accident event is recognized by means of the pre-crash sensor. The door is thus secured against opening when an actual accident event occurs, which is sensed using the crash sensor, and remains closed during the entire accident event sequence. After the accident event lapses, the locking apparatus of the door is unbolted again to enable the occupants to leave the motor vehicle. If no accident event occurs in the first specified interval of time, the locking apparatus of the door is likewise unbolted. The occupants are thus reliably prevented from being hurled out of the motor vehicle during the sequence of the actual accident event. Likewise, no objects endangering the occupants of the motor vehicle can penetrate into the motor vehicle during the accident event.
It is advantageous if the first specified interval of time can be adjusted as a function of the traffic-relevant data recorded by the pre-crash sensor. Through a suitable choice of the length of the first specified interval of time, it can be assured that the occurrence of the accident event, if it actually takes place, occurs in the first specified interval of time. The first specified interval of time can thus be adapted to various possible accident scenarios.
In one refinement of the invention, the second specified interval of time is adjustable as a function of the sensor values of the crash sensor recorded. Through a suitable choice of the length of the second specified interval of time, it can be assured that the locking apparatus of the door remains blocked, during the entire accident event sequence, against an unwanted opening. The length of the second specified interval of time can be correspondingly adapted as a function of the type of accident event.
The safety-relevant data for a driving operation for the pre-crash sensor can be driving state magnitudes. Magnitudes such as motor vehicle speed, yawing, longitudinal and transverse acceleration, brake pedal and accelerator position, and steering angle are used as driving state magnitudes. Furthermore, the status of operating elements such as turn signals and hazard warning lights, as well as the status of sensors and control devices affecting the status of the motor vehicle, can be used as driving state magnitudes.
Environmental data can alternatively or additionally be safety-relevant data for driving operation. Data furnished by environmental sensors, by telematic systems, and by communication of the motor vehicle with other motor vehicles and stationary communication systems can be designated as environmental data. Examples of environmental data are information on the current place, the road category, and the driving lane upon which the particular vehicle is driving. Further environmental data are, among other things, road condition, temperature, weather conditions, and lighting conditions, as well as speed, distance, type and size of motor vehicles driving ahead, alongside, behind, or oncoming, and data provided by other traffic participants.
It is advantageous if the driver activities are evaluated for safety-relevant data for driving operation. Driver activities recorded include, for example, a recognition of eye motion and the direction of view, and also processes of operating elements such as, for example, a steering wheel, a gearshift, and a brake pedal. Through the evaluation of a large number of safety-relevant data, occupant protection safety can be additionally increased.
Further advantageous refinements of the invention are set forth in the dependent claims.